Solar radiation is affected by absorption and emission phenomena during its downward trajectory from the Sun to the Earth's surface and during the upward trajectory detected by satellite sensors. ...This leads to distortion of the ground radiometric properties (reflectance) recorded by satellite images, used in this study to estimate aboveground forest biomass (AGB). Atmospherically-corrected remote sensing data can be used to estimate AGB on a global scale and with moderate effort. The objective of this study was to evaluate four atmospheric correction algorithms (for surface reflectance), ATCOR2 (Atmospheric Correction for Flat Terrain), COST (Cosine of the Sun Zenith Angle), FLAASH (Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes) and 6S (Second Simulation of Satellite Signal in the Solar), and one radiometric correction algorithm (for reflectance at the sensor) ToA (Apparent Reflectance at the Top of Atmosphere) to estimate AGB in temperate forest in the northeast of the state of Durango, Mexico. The AGB was estimated from Landsat 5 TM imagery and ancillary information from a digital elevation model (DEM) using the non-parametric multivariate adaptive regression splines (MARS) technique. Field reference data for the model training were collected by systematic sampling of 99 permanent forest growth and soil research sites (SPIFyS) established during the winter of 2011. The following predictor variables were identified in the MARS model: Band 7, Band 5, slope ( beta ), Wetness Index (WI), NDVI and MSAVI2. After cross-validation, 6S was found to be the optimal model for estimating AGB (R2 = 0.71 and RMSE = 33.5 Mg times ha-1; 37.61% of the average stand biomass). We conclude that atmospheric and radiometric correction of satellite images can be used along with non-parametric techniques to estimate AGB with acceptable accuracy.
Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss and has a large impact on planetary evolution. Three hydrodynamic escape regimes have been identified ...theoretically: energy-limited, recombination-limited, and photon-limited. However, no evidence of these regimes had been reported until now. Here, we report evidence of these three regimes via an analysis of a helium
I
triplet at 10 830 Å and Ly
α
absorption involving a 1D hydrodynamic model that allows us to estimate hydrogen recombination and advection rates. In particular, we show that HD 209458 b is in the energy-limited regime, HD 189733 b is in the recombination-limited regime, and GJ 3470 b is in the photon-limited regime. These exoplanets can be considered as benchmark cases for their respective regimes.
Background
People with intellectual disabilities (IDs) seem to have a lower physical fitness (PF) than their peers without disabilities, which coincides with reduced autonomy, life expectancy and ...quality of life. To assess PF in these individuals, it is necessary to use appropriate tools that permit the assessment of their physical capacities taking into account their specific characteristics. The aim of this work is to study the feasibility and reliability of the Assessing Levels of Physical Activity (ALPHA)‐Fit test battery for adults in a group of men and women with mild to moderate ID.
Methods
Forty‐one adults with ID of both sexes, ranging in age from 20 to 60 years old, participated in the study. To identify the feasibility and reliability of the ALPHA‐Fit test battery for adults, two complete assessments were done for each one of the tests included in the battery. The assessments were performed for a period of no more than 2 weeks (test–retest). An intraclass correlation coefficient was used to determinate test–retest reliability, and a mixed analysis of variance factorial was used for each of the dependent variables. Bland–Altman plots were also used to assess consistency between the two measurements. Feasibility was calculated as the percentage of people who were able to perform the tests correctly (not feasible <50%, fairly feasible 50%–75% and feasible >75%). In order to determine other psychometric properties, minimal detectable change and standard error of measurement (SEM) were also calculated.
Results
Of the 10 tests in the ALPHA‐Fit test battery, eight were shown to be feasible. High reliability was obtained (>0.90) for the variables related to body composition. In the hand‐grip test, reliability was high in the men's group but low in the women's group. Good reliability results were also found (0.80–0.89) in the dynamic sit‐up test for women, but not for men. Fair reliability (0.70–0.79) was found in jump‐and‐reach and neck‐shoulder mobility tests. The variables in the 2‐km walk and agility tests indicated poor reliability. All tests showed SEM values related to high variability. However, Bland–Altman plots showed results related to lack of consistency.
Conclusions
The feasibility and reliability calculations, as well as the SEM values, confirm that not all the tests of the ALPHA‐Fit Test Battery for Adults are suitable for the assessment of PF in adults with ID, probably because of the complexity of the motor fitness tests. The authors emphasise the necessity of making adaptations to the protocols used or of using other tests more appropriate to the characteristics of people with mild to moderate ID.
Ultra-hot Jupiters (UHJs) are gas giants with very high equilibrium temperatures. In recent years, multiple chemical species, including various atoms and ions, have been discovered in their ...atmospheres. Most of these observations have been performed with transmission spectroscopy, although UHJs are also ideal targets for emission spectroscopy due to their strong thermal radiation. We present high-resolution thermal emission spectroscopy of the transiting UHJ KELT-20b/MASCARA-2b. The observation was performed with the CARMENES spectrograph at orbital phases before and after the secondary eclipse. We detected atomic Fe using the cross-correlation technique. The detected Fe lines are in emission, which unambiguously indicates a temperature inversion on the dayside hemisphere. We furthermore retrieved the temperature structure with the detected Fe lines. The result shows that the atmosphere has a strong temperature inversion with a temperature of 4900 ± 700 K and a pressure of 10
−4.8
−1.1
+1.0
bar at the upper layer of the inversion. A joint retrieval of the CARMENES data and the TESS secondary eclipse data returns a temperature of 2550
−250
+150
K and a pressure of 10
−1.5
−0.6
+0.7
bar at the lower layer of the temperature inversion. The detection of such a strong temperature inversion is consistent with theoretical simulations that predict an inversion layer on the dayside of UHJs. The joint retrieval of the CARMENES and TESS data demonstrates the power of combing high-resolution emission spectroscopy with secondary eclipse photometry in characterizing atmospheric temperature structures.
At our institution, the prevalence of clinical isolates of Clostridium difficile with resistance to metronidazole is 6.3%. We observed that initial metronidazole MICs of 16 to 64 mg/liter against ...toxigenic, primary fresh C. difficile isolates, as determined by agar dilution, decreased to 0.125 mg/liter after the isolates were thawed. In this study, we examined the possibility of heterogeneous or inducible resistance. Totals of 14 metronidazole-resistant and 10 metronidazole-susceptible clinical isolates of toxigenic C. difficile were studied. The isolates were investigated for the presence of nim genes by PCR. After the isolates were thawed, susceptibility testing was done by agar dilution, by disc diffusion using a 5-μg metronidazole disc, and by the Etest method. An experiment for determining the effect of prolonged exposure to metronidazole was applied to all resistant isolates and to susceptible control strains. None of the isolates presented the nim genes. All initially metronidazole-resistant C. difficile isolates became susceptible after thawing; however, they presented slow-growing subpopulations within the inhibition zones of both the disk and the Etest strip. All metronidazole-susceptible isolates remained homogeneously susceptible by both methods. After prolonged exposure in vitro to metronidazole, no zone of inhibition was found around the 5-μg disk in any of the metronidazole-resistant isolates, and the MICs as determined by the Etest method ranged from 0.125 to >256 mg/liter, with colonies growing inside the inhibition zone. Our results indicate that (i) resistance to metronidazole was not due to the presence of nim genes, (ii) resistance to metronidazole in toxigenic C. difficile isolates is heterogeneous, and (iii) prolonged exposure to metronidazole can select for in vitro resistance. We recommend routine performance of the disk diffusion method (5-μg metronidazole disk) with primary fresh C. difficile isolates in order to ensure that metronidazole-heteroresistant populations do not go undetected.
Historical climate changes and interspecific gene flow have played an important role in shaping the distribution and genetic diversity of the biota in the Neotropics. In this study, we explored the ...role of both the Pleistocene climate changes and hybridization on the contemporary geographic structure of two Neotropical weedy species: Tithonia tubaeformis and T. rotundifolia.
Distribution shifts under past and current climate conditions were explored through ecological niche modelling (ENM). We then tested these hypotheses using chloroplast microsatellite (cpSSR) data in T. tubaeformis and compared the patterns deduced with those previously reported for T. rotundifolia using the same cpSSR loci. Lastly, we searched for shared haplotypes between species.
Both species exhibited significant downwards altitudinal shifts during the last interglacial (LIG) and the Last Glacial Maximum (LGM). For instance, T. rotundifolia showed large suitable habitat areas since the LIG at xeric conditions in western Mesoamerica. Tithonia tubaeformis showed a ~five‐fold range contraction during the LIG compared to current climate conditions, followed by a range expansion in the LGM. Despite the large shared refugial areas predicted through ENM, we found a low number of shared haplotypes, suggesting a minor role of hybridization in shaping the geographic structure of these species.
Our results provide additional patterns of the population history of the northern Neotropics during the Quaternary, and we suggest that weedy widespread species are a well‐suited group for the study of the effects of historic climatic changes on the biota of this region.
Both species exhibited significant range shifts under past climate conditions; however, genetic data suggests a minor role of hybridization and the main biogeogrpahic barriers in shaping their geographic structure
Context.
Ultra-hot Jupiters have dayside temperatures at which most molecules are expected to thermally dissociate. The dissociation of water vapour results in the production of the hydroxyl radical ...(OH). While OH absorption is easily observed in near-infrared spectra of M dwarfs, which have similar effective temperatures as ultra-hot Jupiters, it is often not considered when studying the atmospheres of ultra-hot Jupiters. Ground-based high-resolution spectroscopy during the primary transit is a powerful tool for detecting molecular absorption in these planets.
Aims.
We aim to assess the presence and detectability of OH in the atmosphere of the ultra-hot Jupiter WASP-76b.
Methods.
We use high-resolution spectroscopic observations of a transit of WASP-76b obtained using CARMENES. After validating the OH line list, we generate model transit spectra of WASP-76b with petitRADTRANS. The data are corrected for stellar and telluric contamination and cross-correlated with the model spectra. After combining all cross-correlation functions from the transit, a detection map is constructed. Constraints on the planet properties from the OH absorption are obtained from a Markov chain Monte Carlo analysis.
Results.
OH is detected in the atmosphere of WASP-76b with a peak signal-to-noise ratio of 6.1. From the retrieval we obtain
K
p
= 232 ± 12 km s
−1
and a blueshift of − 13.2 ± 1.6 km s
−1
, which are offset from the expected velocities. Considering the fast spin rotation of the planet, the blueshift is best explained with the signal predominantly originating from the evening terminator and the presence of a strong dayside-to-nightside wind. The increased
K
p
over its expected value (196.5 km s
−1
) is, however, a bit puzzling. The signal is found to be broad, with a full width at half maximum of 16.8
−4.0
+4.6
km s
−1
. The retrieval results in a weak constraint on the mean temperature of 2700–3700 K at the pressure range of the OH signal.
Conclusions.
We show that OH is readily observable in the transit spectra of ultra-hot Jupiters. Studying this molecule can provide insights into the molecular dissociation processes in the atmospheres of such planets.
Increased global competitiveness has forced corporations to improve how they manage their resources, especially when it comes to resources that give them a competitive advantage. Corporate Reputation ...and Corporate Social Responsibility fulfill that role. This research aims to identify the dimensions that most influence Corporate Reputation and which can be most easily used to achieve a positive result. To do this, the data about 46 companies (from different sectors) contained in the 2015 report “The world's most reputable companies” by Reputation Institute was used. This report identifies seven dimensions which influence Corporate Reputation: products and services, innovation, workplace, governance, citizenship, leadership, and performance. The most important main conclusions are that (a) those companies in which the dimensions of Corporate Social Responsibility (workplace, governance, citizenship) were at an acceptable level, also had an acceptable level of Corporate Reputation. (b) Companies usually carry out passive Corporate Social Responsibility actions, such as those involving citizenship.
Abstract
We study a sample of 28 S0 galaxies extracted from the integral field spectroscopic (IFS) survey Calar Alto Legacy Integral Field Area. We combine an accurate two-dimensional (2D) ...multicomponent photometric decomposition with the IFS kinematic properties of their bulges to understand their formation scenario. Our final sample is representative of S0s with high stellar masses (M⋆/M⊙ > 1010). They lay mainly on the red sequence and live in relatively isolated environments similar to that of the field and loose groups. We use our 2D photometric decomposition to define the size and photometric properties of the bulges, as well as their location within the galaxies. We perform mock spectroscopic simulations mimicking our observed galaxies to quantify the impact of the underlying disc on our bulge kinematic measurements (λ and v/σ). We compare our bulge corrected kinematic measurements with the results from Schwarzschild dynamical modelling. The good agreement confirms the robustness of our results and allows us to use bulge deprojected values of λ and v/σ. We find that the photometric (n and B/T) and kinematic (v/σ and λ) properties of our field S0 bulges are not correlated. We demonstrate that this morpho-kinematic decoupling is intrinsic to the bulges and it is not due to projection effects. We conclude that photometric diagnostics to separate different types of bulges (disc-like versus classical) might not be useful for S0 galaxies. The morpho-kinematics properties of S0 bulges derived in this paper suggest that they are mainly formed by dissipational processes happening at high redshift, but dedicated high-resolution simulations are necessary to better identify their origin.
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